Information recognition technology using Radio Frequency Identification (RFID) requires an RFID tag and an RFID reader.
An RFID tag includes an RFID chip. Required information is recorded on the RFID chip, and the RFID tag transmits the information to an RFID reader via an antenna. Generally, the information stored on the RFID chip is used to identify an object attached to the RFID tag. An RFID system is different from a barcode system in that the RFID system uses radio waves instead of light.
Information recognition technology using RFID has the advantage of being capable of reading a tag over a long distance, as well as operating over a short distance like a barcode reader, and the advantage of being capable of receiving information through an obstacle.
At the UHF band (433 MHz, and 860 to 960 MHz) frequency, the recognition distance of a mobile RFID reader ranges from about 5 to about 10 m, and the communication-enabled distance thereof is about 2 m. It is known that the distance over which recognition can be performed via the mobile RFID reader is a maximum of 2 m in an actual application environment due to RF wave interference attributable to a surrounding environment, etc. Stable signal strength and the ensuring of a sufficient recognition distance are directly related to information recognition rate.
A non-contact type recognition apparatus using RFID essentially requires technology for the ensuring of a sufficient recognition distance and the improvement of recognition rate. For this purpose, a method of increasing the output of a mobile RFID reader or extending the area of an antenna has been considered.
However, there is a limitation to an increase in output, and it cannot be expected that the recognition distance is extended or the recognition rate is improved even when the output is increased. An alternative to this is the extension of the area of an antenna. However, in this case, it is difficult to ensure the large area of the antenna because the portability of the mobile RFID reader must be taken into account.
The information recognition technology using RFID includes known technologies related to the improvement of recognition rate. For example, Korean Patent Application No. 10-2012-0023986 (Patent Document 1) discloses a proposal in which the circuit pattern of an RFID tag is designed to maximally reduce leakage current and to supply sufficient current to an antenna, thereby improving the recognition rate of a tag system. Korean Patent Application No. 10-2010-0051210 (Patent Document 2) discloses a proposal in which precise recognition rate and high-speed tag recognition are implemented using an antenna whose angle is varied according to a location distance value between an RFID tag and a reader. These technologies are all presented to acquire the effect of improving signal recognition rate by increasing the area of the antenna or improving the design of antenna arrangement in common.
It may be expected that the appropriate design of the RFID tag circuit pattern, such as that of Patent Document 1, brings about an improvement in the recognition rate of a tag system as a result. However, in mobile RFID information recognition technology, the performance of the RFID reader that is moving is more important to the determination of recognition rate than the performance of the RFID tag. Accordingly, the design does not influence the ensuring of a stable recognition rate in a non-contact type mobile RFID recognition apparatus.
Although Patent Document 2 discloses a technology of increasing recognition rate by varying the angle of the antenna formed in the body of the RFID reader, the apparatus of this technology cannot be easily moved in the state of being held by the hand, the manipulation of the apparatus is inconvenient, and the movement and carrying of the apparatus is inconvenient. Furthermore, the apparatus is complex in terms of structure, and has low manufacturing efficiency. Additionally, this technology does not present the combination of a terminal device that outputs recognized information, and thus the apparatus has a structure that is inconvenient for real-time use during movement.
Meanwhile, examples of the structures of RFID readers that have simplified structures and are easy to move and carry are disclosed in Korean Patent Application Publication No. 10-2008-0056327 (Patent Document 3) entitled “Portable Barcode Reader” and Korean Patent Application Publication Nos. 10-2008-0056328 and 10-2008-0056329 entitled “RFID Reader on which Mobile Terminal is Mountable.” However, these technologies have a limitation to the ensuring of a stable signal recognition rate.